#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
#define yes cout << "YES\n"
#define no cout << "NO\n"
#define F first
#define S second
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define int long long
const int N = 100010;
vector<pair<int, int>> adj[N];
int n, s, q, e;
int h[N], cl[N], tin[N], tout[N];
int dist[N];
vector<pair<pair<int, int>, int>> edges;
int p[17][N];
bool isp[N];
int timer=-1;
int cst[N];
vector<int> sps;
vector<vector<int>> precalc;
void dfs(int v, int par){
if(isp[v])dist[v]=0;
h[v]=h[par]+1;
p[0][v]=par;
for(int i=1; i<=16; i++){
p[i][v]=p[i-1][p[i-1][v]];
}
tin[v]=++timer;
for(auto to : adj[v]){
if(to.F!=par){
dfs(to.F, v);
dist[v]=min(dist[v], dist[to.F]+to.S);
}
}
tout[v]=timer;
}
int anc(int a, int b){
int ret=a;
for(int i=0; i<17; i++){
if(b&(1<<i)){
ret=p[i][ret];
}
}
return ret;
}
void solve(){
cin >> n >> s >> q >> e;
for(int i=0; i< n-1; i++){
int x, y, z;
cin >> x >> y >> z;
edges.pb({{x, y}, z});
adj[x].pb({y, z});
adj[y].pb({x, z});
}
for(int i=0; i<=n; i++)dist[i]=1e18;
for(int i=0; i< s; i++){
int x;
cin >> x;
sps.pb(x);
isp[x]=1;
}
dfs(e, 0);
tin[0]=0; tout[0]=1e9;
for(auto & p : edges){
if(h[p.F.F]>h[p.F.S])swap(p.F.F, p.F.S);
cst[p.F.S]=p.S;
}
int sq=300;
precalc.pb({});
for(int i=1; i<=n; i++){
vector<int> prec;
if(h[i]%sq==0){
int x=i;
int mn=dist[x];
prec.pb(mn);
int pth=0;
while(x!=e){
pth+=cst[x];
x=p[0][x];
mn=min(mn, dist[x]+pth);
prec.pb(mn);
}
}
precalc.pb(prec);
}
while(q--){
int ind, v;
cin >> ind >> v;
pair<pair<int, int>, int> edge = edges[ind-1];
if(h[edge.F.S]>h[v]){
cout << "escaped\n";
continue;
}
int str=anc(v, h[v]-h[edge.F.S]);
if(str==edge.F.S){
if(dist[str]==1e18){
cout << "oo\n";
continue;
}
int mn=dist[v];
int pth=0;
while(mn>0 && v!=str){
if(precalc[v].size() && h[v]-h[str]>100){
mn=min(mn, pth+precalc[v][h[v]-h[str]]);
break;
}
pth+=cst[v];
if(mn<=pth)break;
v=p[0][v];
mn=min(mn, pth+dist[v]);
}
cout << mn << '\n';
}
else cout << "escaped\n";
}
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
solve();
}
